wname = 'db2'
% load image
load detfingr
[m,n] =  size(X);
m = m-rem(m,8);
n = n-rem(n,8);
X = X(1:m,1:n);

% compute DWT
[CA1,CH1,CV1,CD1] =dwtper2(X,wname);
[CA2,CH2,CV2,CD2] =dwtper2(CA1,wname);
[CA3,CH3,CV3,CD3] =dwtper2(CA2,wname);

% normalize

CA1m = CA1-min(CA1(:));
CV1m = CV1-min(CV1(:));
CH1m = CH1-min(CH1(:));
CD1m = CD1-min(CD1(:));

CA1m = CA1m/max(CA1m(:));
CV1m = CV1m/max(CV1m(:));
CH1m = CH1m/max(CH1m(:));
CD1m = CD1m/max(CD1m(:));


CA2m = CA2-min(CA2(:));
CV2m = CV2-min(CV2(:));
CH2m = CH2-min(CH2(:));
CD2m = CD2-min(CD2(:));

CA2m = CA2m/max(CA2m(:));
CV2m = CV2m/max(CV2m(:));
CH2m = CH2m/max(CH2m(:));
CD2m = CD2m/max(CD2m(:));

CA3m = CA3-min(CA3(:));
CV3m = CV3-min(CV3(:));
CH3m = CH3-min(CH3(:));
CD3m = CD3-min(CD3(:));

CA3m = CA3m/max(CA3m(:));
CV3m = CV3m/max(CV3m(:));
CH3m = CH3m/max(CH3m(:));
CD3m = CD3m/max(CD3m(:));



figure(1)
imshow(X,[]);
title('original');
pause
figure(2)
imshow([CA1m,CV1m; CH1m,CD1m],[]);
title('stage 1');
pause
figure(3)
imshow([[CA2m,CV2m; CH2m,CD2m],CV1m; CH1m,CD1m],[]);
title('stage 2');
pause
figure(4)
imshow([[[CA3m,CV3m; CH3m,CD3m],CV2m; CH2m,CD2m],CV1m; CH1m,CD1m],[]);
title('stage 3');